Transient Behavior of Near Frictionless Carbon Films in Reciprocating Microtribometery in Low Humidity Inert Environments

Microtribological measurements of near frictionless carbon (NFC) films in controlled gaseous environments show that water vapor plays a role in the friction coefficient. These experiments also show that the NFC films initially have high friction in argon, which then decreases. This high friction does not reform over extended periods of exposure to Ar and low partial pressures of H₂O and O₂. Tests varying water vapor pressure show that under certain humidity conditions the friction coefficient can increases to values seen after extended periods of environmental exposure.